Electrochemical devices such as lithium ion secondary batteries, electric double-layer capacitors, and lithium ion capacitors have characteristics such as compact size, light weight, high energy-density, and the ability to be repeatedly charged and discharged, and are used in a wide range of applications. These electrochemical devices typically include an electrode assembly, an electrolysis solution, and a casing that houses the electrode assembly and the electrolysis solution in a tightly sealed manner. The electrode assembly is a laminate of a plurality of electrodes and one or more separators that isolate the electrodes from one another and prevent short-circuiting between the electrodes.
Studies have been conducted in relation to techniques for adhering an electrode assembly and a casing to one another in an electrochemical device such as described above so as to secure the electrode assembly to the casing and ensure safety and the like of the electrochemical device. In one example, PTL 1 reports that when sealing tape for a secondary battery including a first adhesive layer, having an adhesive surface, and a second adhesive layer, having an adhesive surface at an opposite side to the adhesive surface of the first adhesive layer, is used by adhering the adhesive surface of the first adhesive layer to an outer surface of an electrode assembly and adhering the adhesive surface of the second adhesive layer to an inner surface of a casing, the electrode assembly can be prevented from moving within the casing, and safety and the like of a secondary battery can be improved.